1-methylspiro[2,3-dihydro-1H-naphthalene-4,5'-imidazolidine]-2',4'-dione   、                                                                                      
2-溴乙酸苄酯                                                                                                                                                              在
                                                                                                                                                                                 
双(三甲基硅烷基)氨基钾                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃   、                                                                                         
N,N-二甲基甲酰胺                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 4S,4'R-benzyl (4'-methyl-2,5-dioxo-3',4'-dihydro-2'H-spiro[imidazolidine-4,1'-naphthalene]-1-yl)acetate   、                                                                                             4R,4'R-benzyl (4'-methyl-2,5-dioxo-3',4'-dihydro-2'H-spiro[imidazolidine-4,1'-naphthalene]-1-yl)acetate   、                                                                                             4S,4'S-benzyl (4'-methyl-2,5-dioxo-3',4'-dihydro-2'H-spiro[imidazolidine-4,1'-naphthalene]-1-yl)acetate   、                                                                                             (4R,4'S)-benzyl (4'-methyl-2,5-dioxo-3',4'-dihydro-2'H-spiro[imidazolidine-4,1'-naphthalene]-1-yl)acetate